Distraction extension injuries of the cervical spine.

Twenty-four consecutive patients with cervical distraction extension injuries were retrospectively reviewed to study the safety and efficacy of various treatment protocols in this type of cervical spine injury. Sixteen of 24 patients with cervical distraction extension injuries underwent surgical stabilization. All patients undergoing surgical stabilization were noted to have a stable fusion at their latest follow-up. There were three instances of surgically related neurologic deterioration as a result of over-distraction of the anterior column interspace at the time of graft placement. The overall mortality rate was 42% in this aged patient population. Anterior reconstruction of the cervical spine with an anterior cervical graft and plate acting as a tension band is the ideal treatment method for stabilization of acute distraction extension injuries involving primarily the soft tissue structures (anterior longitudinal ligament and intervertebral disc). Type 2 injuries, depending on the degree of displacement and the adequacy of closed reduction, may need to be approached initially posteriorly to obtain adequate alignment, followed by an anterior reconstructive procedure. Great care should be taken during anterior graft placement to avoid over-distraction of the spine. If nonsurgical intervention is selected, close regular radiographic follow-up is necessary to detect early vertebral malalignment, which may predispose to spinal cord dysfunction. Older patients sustaining this injury have a high mortality rate.

Injuries of the thoracolumbar spine associated with restraint use in head-on motor vehicle accidents.

Many authors have described spinal and bodily injuries associated with seat belt use. However, most reports have focused primarily on lap seat belts and resultant flexion-distraction injuries. This retrospective chart review studies the relation between the specific type of restraint or air bag and the resultant thoracolumbar spinal injury subtype and associated bodily injuries. The charts of 221 patients who had sustained thoracolumbar fractures in motor vehicle accidents during a 10-year period were reviewed, and 37 patients were identified whose accidents were clearly described as a frontal collision and whose specific form of restraint was recorded. Among the 15 patients who used a shoulder strap and lap belt device (three-point restraint), 12 patients sustained burst fractures (80%) compared with 4 of the 14 patients (28.6%) restrained with lap seat belts alone. Life-threatening intraabdominal injuries occurred in 57.1% of lap-belted victims and in 26.7% of patients who used three-point restraints, and the character of these injuries also differed. No patients in an automobile in which an air bag deployed sustained major associated bodily injuries. Among restrained occupants of head-on motor vehicle accidents who have sustained a thoracolumbar fracture, patients using lap belts are more likely to sustain the classic flexion-distraction injury patterns, whereas patients using three-point restraints may sustain a higher incidence of burst fractures. In addition, three-point restraints are associated with a decreased risk of intraabdominal injury compared with lap seat belts.

Magnetic resonance evaluation of the intervertebral disc, spinal ligaments, and spinal cord before and after closed traction reduction of cervical spine dislocations.

STUDY DESIGN: A prospective clinical study using magnetic resonance imaging of the cervical spine in a consecutive series of patients with cervical spine dislocations. OBJECTIVES: To determine the incidence of intervertebral disc herniations and injury to the spinal ligaments before and after awake closed traction reduction of cervical spine dislocations. SUMMARY OF BACKGROUND DATA: Prior series in which the prereduction imaging of disc herniations in the dislocated cervical spine are described have been anecdotal and have involved small numbers of patients. In addition, no uniform clinical criteria to define the presence of an intervertebral disc herniation in the dislocated cervical spine has been described. The incidence of disc herniations in the unreduced dislocated cervical spine is unknown. METHODS: Eleven consecutive patients with cervical spine dislocations who met the clinical criteria for an awake closed traction reduction had prereduction and postreduction magnetic resonance imaging. Using strict clinical criteria for the definition of an intervertebral disc herniation, the presence or absence of disc herniation, spinal ligament injury, and cord injury was determined. Neurologic status before, during, and after the closed reduction maneuver was documented. RESULTS: Disc herniations were identified in 2 of 11 patients before reduction. Awake closed traction reduction was successful in 9 of the 11 patients. Of the nine patients with a successful closed reduction, two had disc herniations before reduction, and five had disc herniations after reduction. No patient had neurologic worsening after attempted awake closed traction reduction. CONCLUSIONS: The process of closed traction reduction appears to increase the incidence of intervertebral disc herniations. The relation of these findings, however, to the neurologic safety of awake closed traction reduction remain unclear.

Efficacy of magnetic resonance imaging in the evaluation of posterior cervical spine fractures.

STUDY DESIGN: A retrospective study using two independent, blinded musculoskeletal radiologists to evaluate the sensitivity, specificity, and predictive value of cervical spine magnetic resonance imaging in detecting posterior element fractures of the cervical spine. OBJECTIVE: To evaluate the sensitivity, specificity, and predictive value of magnetic resonance imaging, using computed tomographic scanning as the gold standard, in the diagnosis of posterior element cervical spine fractures. SUMMARY OF BACKGROUND DATA: Few investigators have evaluated the accuracy of magnetic resonance imaging in the determination of cervical spine fractures. METHODS: From January 1994 through June 1996, 75 cervical spine fractures in 32 patients were confirmed by computed tomography. Two musculoskeletal radiologists who were blinded to the clinical history and presence or absence of cervical injury among the study population, independently evaluated each cervical magnetic resonance image recording the presence or absence of soft tissue or bony injury. RESULTS: The overall sensitivity and specificity rates for the diagnosis of a posterior element fracture by magnetic resonance imaging was 11.5% and 97.0%, respectively. The positive predictive value for this group was 83%, and the negative predictive value was 46%. In reference to anterior fractures, the sensitivity was 36.7% and the specificity 98%. Positive and negative predictive values were 91.2% and 64%, respectively. CONCLUSIONS: Magnetic resonance imaging was not effective in recognizing bony injury to the cervical spine and in particular was not as sensitive or as specific as computed tomography in identifying cervical spinal fractures. Computed tomography remains the study of choice for the detection and precise classification of bony injuries to the cervical region, especially when plain radiographs are difficult to evaluate. Magnetic resonance imaging, although not as effective as computed tomography in defining specific bony disorders, remains the gold standard in the evaluation of spinal cord injury, occult vascular injury, and intervertebral disc disruption (hyperextension injury), including herniation and other soft tissue disorders (hematoma, ligament tear).

"En-bloc" vertebrectomy in the mobile lumbar spine.

BACKGROUND: Primary tumors of the vertebral bodies have previously been treated with total or subtotal excision in a piecemeal fashion (intralesional excision). Radiation therapy has been used to help control tumor growth. Recurrence rates with an intralesional, piecemeal removal of vertebral tumors have been unacceptably high. This study describes a method to excise a lumbar vertebra "en-bloc," and in the process, to perform a marginal (extralesional) resection of a primary tumor of the mobile lumbar spine that allows for a potential surgical cure. METHODS: A combined posterior-anterior procedure allows for an extralesional, marginal resection of the tumor and the involved vertebra. All posterior bony elements, including the pedicles and the adjacent intervertebral discs, are removed via a posterior approach. An anterior, retroperitoneal approach is then used to remove the vertebral body/tumor as a single specimen. The nerve roots at the involved levels are spared and the spine is instrumented and fused both posteriorly and anteriorly. RESULTS: Three patients successfully had combined posterior-anterior resections of lumbar vertebral chordomas. No permanent neurological complications occurred. Overall morbidity of the procedure was acceptable. At 31-month follow-up, no tumor recurrence has been detected. CONCLUSIONS: "En-bloc" resection of a primary vertebral tumor of the lumbar spine is technically demanding, but potentially curative. The alternative approaches-intralesional excision, radiation therapy, or a combination-are unable to cure these tumors. Long-term, 10-year follow-up will be necessary to confirm whether this en-bloc approach provides a surgical cure.

Usefulness of MRI in isolated upper cervical spine fractures in adults.

A prospective analysis of patients admitted with isolated upper cervical spine fractures and who had magnetic resonance (MR) imaging performed within 48 h of the inciting traumatic event was completed to determine the clinical usefulness and cost effectiveness of routine MR screening. In patients with an identified neurologic deficit, MR findings changed the treatment of 25% (one of four) of the patients, whereas MR findings did not change the treatment of any patient identified without a neurologic deficit. We recommend that in adult patients with an isolated upper cervical spine fracture, MR should not be routinely ordered in patients without a neurologic deficit. This advanced imaging modality is not a useful or cost-effective screening device for patients presenting with a fracture of the upper cervical spine without neurologic deficit.

Accuracy of SPECT scanning in diagnosing pseudoarthrosis: a prospective study.

The present study attempted to analyze the efficacy of single photon emission computed tomography (SPECT) in diagnosing pseudoarthrosis after fusion using surgical exploration as the gold standard. This study examined the SPECT scans of 38 patients before they underwent surgical exploration of their fusion mass for suspected pseudoarthrosis or in conjunction with instrumentation removal. Surgical findings were compared with the radiologists' findings to determine the efficacy of SPECT in diagnosing pseudoarthrosis. Radiographic determination of pseudoarthrosis has been difficult after attempted fusion of the spine. Multiple radiographic modalities have been touted as accurate depicters of the failure of spinal fusion. However, no method has been found to be highly accurate in the clinical setting. Thirty-eight patients (mean age = 42.8, 21 males/17 females, 35 of 38 with instrumentation) underwent SPECT scans before surgical exploration of their fusion mass for suspected pseudoarthrosis or in conjunction with instrumentation removal as part of this prospective study. The average interval from their fusion procedure until their SPECT scan was 23.9 months (range, 9-120 months). All surgical findings were recorded with regard to solidity of the fusion and the level of the possible pseudoarthrosis. All SPECT scans were read at a time after surgery by an independent nuclear radiologist who had not read their SPECT scans before surgery and who did not know the results of exploration. Results of the radiologist's reading were then compared with surgical exploration findings, and sensitivity and specificity was calculated. There were 24 solid fusions and 14 pseudoarthroses. SPECT scans correctly identified 7 of the 14 pseudoarthroses and 14 of the 24 solid fusions. This represents a sensitivity of 0.50 and a specificity of 0.58. SPECT scanning correctly diagnosed the one solid fusion and two pseudoarthrosis patients in the three patients who had no instrumentation. This study demonstrates that SPECT scanning alone is inaccurate in diagnosing pseudoarthrosis when using surgical exploration as the gold standard. Given recent pressures for cost containment, we cannot recommend SPECT scanning as a routine modality for use in the diagnosis of pseudoarthrosis. We cannot define the accuracy of SPECT scanning used together with computed tomography scans, plain films, or other radiographic modalities in the diagnosis of pseudoarthrosis.

Neurologic deterioration after cervical spinal cord injury.

Neurologic deterioration after cervical spinal cord injury (SCI) at a regional spinal cord center was examined. This study examined the incidence of neurologic deterioration as well as associated risk factors in our patient population. Up to 5.8% of cervical SCI patients have been noted to deteriorate neurologically after admission. Risk factors have been early surgery, halo application, traction, and Stryker frame rotation. All cervical SCI patients admitted between 1978 and 1993 who had neurologic deterioration were studied for characteristics of their event, operative status, risk factors, mortality, and neurologic return at 1 year postinjury. Patients were divided into minor and major groups based on the degree of neurologic loss. Nineteen of 1,031 patients were identified as neurologically deteriorated (1.84%). There were 8 major and 11 minor group patients. The average time from injury to deterioration was 3.95 days. Of 10 patients undergoing surgery at < or =5 days, 8 deteriorated postoperatively. Potential risk factors were ankylosing spondylitis (three patients), sepsis (four patients), and intubation (four patients). Neurologic recovery at 1 year showed that 11 of 12 patients were improved. Neurologic deterioration occurred in 1.84% of our patients. Deteriorations were associated with surgery at <5 days after injury, ankylosing spondylitis, sepsis, and intubation.

Long-term evaluation of vertebral artery injuries following cervical spine trauma using magnetic resonance angiography.

STUDY DESIGN: A prospective study to determine the long-term outcome of traumatically induced vertebral artery injuries. Magnetic resonance angiography was performed at the time of cervical injury and at a follow-up office visit. OBJECTIVE: To determine the long-term outcome in terms of arterial flow competency of traumatically induced vertebral artery injuries. SUMMARY OF BACKGROUND DATA: Vertebral artery injury associated with cervical spine trauma has been well documented; however its healing or nonhealing potential has not been elucidated. METHODS: During the 7-month period from July 1993 to January 1994, all patients admitted to the authors' institution with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of the cervical spine to determine the patency of their vertebral arteries. Magnetic resonance angiography was performed at the time of injury and at a follow-up office visit. Twelve of 61 patients were found to have a lack of signal flow within one of their vertebral vessels during this study period. RESULTS: Eighty-three percent of the patients (five of six) who were available for follow-up observation in this study did not manifest flow reconstitution of their vertebral arteries after an average 25.8-month follow-up period. CONCLUSIONS: According to these data, most patients with vertebral artery injuries after nonpenetrating cervical spine trauma do not reconstitute flow in the injured vertebral arteries. This lack of flow must be considered if future surgery in this region of the cervical spine is contemplated.

The benefits of early decompression in cervical spinal cord injury.

Decompression and stabilization have been shown to improve neurologic outcome in cases of cervical spine trauma with proven compression of the spinal cord. This paper reviews experimental and clinical research to clarify the benefits of early surgery for cervical spinal cord injury. The direct clinical benefit of early surgery is a theoretic improvement in neurologic recovery over that of delayed surgery. Additional benefits of early surgery include the clinical advantages of a decreased length of hospitalization and its associated complications and a decreased time to rehabilitation and mobilization. Proper, timely surgical intervention can better the physiologic environment so as to allow for maximum neurologic improvement.

Neurologic outcome of early versus late surgery for cervical spinal cord injury.

STUDY DESIGN: A prospective analysis evaluating neurologic outcome after early versus late surgery for cervical spinal cord trauma. OBJECTIVES: The study was conducted to determine whether neurologic and functional outcome is improved in traumatic cervical spinal cord-injured patients (C3-T1, American Spinal Injury Association grades A-D) who had early surgery (<72 hours after spinal cord injury) compared with those patients who had late surgery (>5 days after spinal cord injury). SUMMARY OF BACKGROUND DATA: There is considerable controversy as to the appropriate timing of surgical decompression and stabilization for cervical spinal cord trauma. There have been numerous retrospective studies, but no prospective studies, to determine whether neurologic outcome is best after early versus late surgical treatment for cervical spinal cord injury. METHODS: Patients meeting appropriate inclusion criteria were randomized to an early (<72 hours after spinal cord injury) or late (>5 days after spinal cord injury) surgical treatment protocol. The neurologic and functional outcomes were recorded from the acute hospital admission to the most recent follow-up. RESULTS: Comparison of the two groups showed no significant difference in length of acute postoperative intensive care stay, length of inpatient rehabilitation, or improvement in American Spinal Injury Association grade or motor score between early (mean, 1.8 days) versus late (mean, 16.8 days) surgery. CONCLUSIONS: The results of this study reveal no significant neurologic benefit when cervical spinal cord decompression after trauma is performed less than 72 hours after injury (mean, 1.8 days) as opposed to waiting longer than 5 days (mean, 16.8 days).

Bivector traction for unstable cervical spine fractures: a description of its application and preliminary results.

The management of acute, displaced odontoid fractures requires the restoration of sagittal alignment and rigid external or internal immobilization to prevent late instability and achieve union. This report introduces a new traction technique for the reduction of posteriorly displaced type 2 odontoid fractures. Seven patients with traumatic injuries to the dens were placed in bivector traction for an awake closed reduction. Sagittal alignment was restored and maintained in all patients with no neurologic deterioration or traction-related complications during an average of 11 days (range, 2-28 days) in traction. The overall sagittal alignment corrected from an initial average of 12.2 mm (range, 5-22 mm) of posterior displacement to an average of 1.1 mm (range, 0-3 mm) at the completion of reduction. Only one patient had residual angulation, which measured 5 degrees. Three patients achieved an osseous union and the remaining four required a posterior C1-C2 fusion for nonunion. Although operative stabilization may be the preferred approach in this patient population and injury pattern, we conclude that bivector traction is a safe and effective technique for the initial management of posteriorly displaced odontoid fractures. In addition, its role can be expanded to the closed reduction of lower cervical spine fractures in patients with fixed flexion deformities secondary to ankylosing spondylitis or disseminated intraosseous segmental hyperostosis.

Steroids and gunshot wounds to the spine.

OBJECTIVE: The second National Acute Spinal Cord Injury Study demonstrated that there were neurological benefits from "spinal cord injury" doses of methylprednisolone for blunt spinal cord injuries. In this review, we examined the relative risk/benefit ratio of intravenously treating spinal gunshot wound victims with steroids. METHODS: A retrospective review was conducted of 254 consecutive patients who were treated between 1979 and 1994 for gunshot wounds to the spine (C1-L1) and a spinal cord injury. Three subgroups were established based on the administration of the steroids methylprednisolone (National Acute Spinal Cord Injury Study 2 protocol), dexamethasone (initial dose, 10-100 mg), and no steroids. All patients who received steroids were initially treated at another hospital and then transferred. No patients received steroids at our institution. The data analyzed included neurological outcome and infectious and noninfectious complications. RESULTS: No statistically significant neurological benefits were demonstrable from the use of steroids (methylprednisolone, dexamethasone). Infectious complications were increased in both groups receiving steroids (not statistically significant). Gastrointestinal complications were significantly increased in the dexamethasone group (P = 0.021), and pancreatitis was significantly increased in the methylprednisolone group (P = 0.040). The mean duration of follow-up was 56.3 months. CONCLUSION: In this retrospective, nonrandomized review, no neurological benefits were detectable from intravenously administered steroids after a gunshot wound to the spine. Both infectious and noninfectious complication rates were higher in the groups receiving steroids. Patients who sustain a spinal cord injury secondary to a gunshot wound to the spine should not be treated with steroids until the efficacy of such treatment is proven in a controlled study.

Potential large vessel injury during thoracolumbar pedicle screw removal. A case report.

STUDY DESIGN: A case study of a previously unreported complication of unsuccessful broken pedicle screw removal in the thoracolumbar spine is presented. OBJECTIVES: To emphasize an increased awareness of the potential for large vessel injury during difficult broken pedicle screw removal in the thoracolumbar spine and to encourage the thorough evaluation of indications for the removal of any broken distal fragment in a vertebral body. SUMMARY OF BACKGROUND DATA: Reported complications of pedicle screw removal include the inability to remove the distal screw fragment, nerve root injury, and dural sheath violation. Damage to anterior vascular structures, including the vena cava, iliac arterial and venous systems, and aorta, has not yet been reported in association with difficult broken pedicle screw removal. METHODS: An instrument designed to capture the distal end of a screw fragment through an interference fit resulted in inadvertent screw migration into the retroperitoneal space. Plain roentgenograms and computed tomography were used to document this complication, revealing the close proximity of the screw fragment to the aorta. RESULTS: Expedient recognition of the anteriorly migrated screw fragment with its subsequent removal resulted in a satisfactory outcome. CONCLUSION: Great care must be taken during the removal of broken pedicle screws to prevent injury to surrounding structures. Additionally, indications for the removal of distal screw fragments must be carefully established. Instruments designed to capture the end of the distal screw fragment through an interference fit may allow anterior screw migration to occur, particularly in osteoporotic bone.

Vertebral artery occlusion associated with cervical spine trauma. A prospective analysis.

STUDY DESIGN: Radiographs and charts of 61 patients sustaining cervical spine trauma were studied prospectively to determine the incidence of vertebral artery injuries and possible correlative factors. Statistical analysis was conducted using chi-square testing of a two-way classification system. OBJECTIVES: To elucidate the incidence of vertebral artery injuries associated with cervical spine trauma, and to determine the value of various factors in predicting the existence of a vertebral artery injury. SUMMARY OF BACKGROUND DATA: During a 7-month period, 61 patients (41 male patients, 20 female; average age, 40.3 years) with cervical spine trauma were studied. METHODS: All patients admitted to the authors' hospital with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of their cervical spine. All magnetic resonance angiographies were examined for vertebral artery injury. Data on demographics and the injury were recorded. RESULTS: Complete disruption of blood flow through the vertebral artery was demonstrated by magnetic resonance angiography in 12 of the 61 patients (19.7%). Ten of the 12 patients (83%) had either flexion distraction or flexion compression injuries. Age, sex, mechanism of injury, neurologic impairment, and associated injuries were not statistically significant in predicting the presence of a vertebral vessel occlusion. CONCLUSION: The findings in this study may support the need for vertebral vessel evaluation in selective patients, particularly those with flexion injuries and with neurologic symptoms consistent with vertebral artery insufficiency syndrome that do not correlate with the presenting bone and soft-tissue injuries.